Seismic composition system

Claim 2

In a method for digitally compositing seismic data derived from a plurality of seismic channels, each channel including an amplifier for amplifying the individual record data in each channel, the record data including both an indication of the amplitude of the record data at the output of said amplifier and of the gain of the amplifier corresponding to said amplitude indication, the steps of: providing a plurality of recording channels on a first storage means; periodically recording on said first storage means composited digital data including both an indicAtion of the amplitude of the composited data and a gain indication; periodically storing in a second storage means the output digital seismic record data from said channels including amplitude and gain data; periodically and simultaneously reading out from said first storage means said recorded composited data and from said second storage means said seismic record data; normalizing the readout record data or the composited data so that their respective gains are always equal to the lower gain value of either the composited data or the record data; combining the normalized data with the other readout data to form new composited data; and recording the new composited data on said first storage means for compositing with new record data.

Claim 3

The method of claim 1 and; comparing the respective gains of said recorded composited data and said seismic record data; producing a shift-control signal from the comparison step; storing the readout data in shift registers; and determining from the shift-control signal the direction and amount of shift in the registers to obtain the normalized record data.

Claim 4

In a system for digitally compositing seismic data derived from a plurality of seismic channels, each channel including an amplifier for amplifying the individual record data in each channel, the record data including both an indication of the amplitude of the record data at the output of said amplifier and of the gain of the amplifier corresponding to said amplitude indication, the system comprising: a first storage means defining a plurality of recording channels for periodically recording composited data therein including both an indication of the amplitude of the composited data and a gain indication; second storage means for periodically storing therein the output record data from said seismic channels including gain record data and amplitude record data; readout means for periodically reading out from said first storage means said recorded composited data and from said second storage means said record data including gain record data; normalizing means coupled to said readout means and adapted to normalize said readout data so that the gains of said record data and of said composited data always correspond to the lowest gain-valued data; combining means coupled to said normalizing means for combining the normalized data with the other readout data to form new composited data; and means to store said new composited data on said first storage means for compositing with new seismic record data.

Claim 5

In a system for digitally compositing seismic data derived from a plurality of seismic channels, each channel including an amplifier for amplifying the individual record data in each channel, the record data including both an indication of the amplitude of the record data at the output of said amplifier and of the gain of the amplifier corresponding to said amplitude indication, the system comprising: a first storage means defining a plurality of recording channels for periodically recording composited data therein including both an indication of the amplitude of the composited data and a gain indication; second storage means for periodically storing therein the output record data from said seismic channels including gain record data and amplitude record data; readout means for periodically reading out from said first storage means said recorded composited data and from said second storage means said record data including gain record data; normalizing means coupled to said readout means and adapted to normalize said readout data so that the gains of said record data and of said composited data always correspond to the lowest gain-valued data; combining means coupled to said normalizing means for combining the normalized data with the other readout data to form new composited data; and means to store said new composited data on said first storage means for compositing with new seismic record data.

Claim 6

The system of claim 3 wherein, said normalizing means changes the amplitude of said seismic record data in dependence upon the difference between the gain of said seismic record data and the gain of said composited data.

Claim 7

The system as recited in claim 4 and further including; means to compare the respective gains of said stored composited data and said stored seismic record data to produce a shift-control signal; shift registers for storing said readout data; and said shift control signal determining the direction and amount of shift in one of said registers to obtain said normalized data.

Claim 8

The system of claim 3 wherein, said combining means includes an adder for adding said normalized data to said other readout data; and a memory for storing the output of said adder.